ABSTRACT: This is the user guide of the Maury Microwave WR187 Waveguide SSLT Calibration Kit for models WR187CK10\12 Series. The WR187CK10\12 series of waveguide SSLT calibration kits are designed to provide accurate calibrations of network analyzers in the WR187 band of 3.95 – 5.85 GHz. Each of these kits includes all the necessary SSLT calibration standards and associated hardware needed for the accurate calibration of most network analyzers.